1. Field of the Invention
The present invention relates to a data processing system including at least two processing units having different throughputs for a main storage unit.
2. Description of the Related Art
Recently, in an effort to provide a more rapid processing, vector computers have been developed. But even in such a computer, when carrying out an ultra-large scale scientific calculation, sometimes it is not possible for all of the data to be stored at the same time in a main storage unit, thus increasing the overhead of the input/output processing. Accordingly, to reduce this overhead, an extended storage unit is provided in addition to the main storage unit.
Note, an extended storage control unit for the extended storage unit has a smaller throughput for the main storage unit than other units such as a vector unit.
In a computer system having a plurality of processing units, such as the vector unit, the extended storage control unit, and the like, the processing limits have different throughputs for the main storage unit. When the processing units perform sequential access upon the main storage unit simultaneously, there may be a problem in that the throughput of one processing unit, such as the vector unit having a large throughput, becomes the same as that of another processing unit, such as the extended storage control unit having a small throughput, thereby reducing the data processing efficiency of the system. This will be later explained in more detail.